<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
		<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
		
		<!-- 可选的 Bootstrap 主题文件（一般不用引入） -->
		<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap-theme.min.css" integrity="sha384-6pzBo3FDv/PJ8r2KRkGHifhEocL+1X2rVCTTkUfGk7/0pbek5mMa1upzvWbrUbOZ" crossorigin="anonymous">
		
		<!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
		<script src="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js" integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd" crossorigin="anonymous"></script>
	
	<style>
		.login-box{
			margin-top: 200px;
			padding: 50px;
			border-radius: 20px;
			position: relative;
		}
		.login-box>div{
			margin-bottom: 20px;
		}
		.login-box>.into{
			position: absolute;
			background-color: white;
			width: 100%;
			height: 100%;
			z-index: -1;
			top: -5px;
			left: -5px;
			opacity: 0.7;
			border-radius: 20px;
		}
		body{
			background: url(imgs/20210724_214029.jpg ) no-repeat;
			background-size: cover;
		}
		html{
			height: 100%;
			overflow: hidden;
		}
	</style>
	</head>
	<body>
<div class="row">
<div class="col-md-4 col-md-offset-4 login-box">
	<div class="into"></div>
<div class="input-group input-group-lg">
	<span class="input-group-addon">账号</span>
	<input type="text" class="form-control" placeholder="用户名">
</div>
<div class="input-group input-group-lg">
	<span class="input-group-addon">密码</span>
	<input type="text" class="form-control" placeholder="密码">
</div>
<div>
<button type="button" class="form-control btn btn-primary">登录</button>
</div>
</div>

	</body>
</html>
